1. Field of the Invention
The present invention relates to a method of manufacturing a graphene composite, and more particularly to a method of manufacturing a graphene composite that is suitable as an active material of a supercapacitor.
2. Description of the Related Art
Recently, the demand for supercapacitors, which are next-generation energy storage devices for replacing or supplementing lithium secondary batteries, has been rapidly increasing, and interest in supercapacitors has been growing. Accordingly, efforts have been continuously made to develop a 2D-structured graphene electrode having a large specific surface area and high electric conductivity.
A method of obtaining the reduced graphene oxide by oxidizing graphite, separating layers of graphite oxide in solution, and reducing the resultant graphene oxide has a merit in that graphene-based materials are obtained in a large amount.
Examples of subsequently developed related technologies include a method for stripping graphite oxide using a microwave technology (microwave radiation), and graphite having a particle size of about 150 μm is used as an initial starting material to manufacture graphite oxide.
In order to apply a microwave to the manufactured graphite oxide to thus manufacture the reduced graphene oxide (RGO), a conducting agent having high electric conductivity must be added. Conventionally, the conducting agent, such as super-P (registered trademark) and acetylene black, is added in an amount of about 10% for use thereof.
The conducting agent remains in the final material of the RGO manufactured using the aforementioned method, but the RGO is used without separation in most cases because it is difficult to separate the conducting agent. Further, an additional conducting agent is added to manufacture a slurry electrode using the RGO as the active material.